There's a flea outbreak at 101 Dalmatian Street! Dylan springs into action by forcing the infected into quarantine. But the source of the infestation turns out to be quite the surprise.
While Dylan is showing off the new space rock he received, Dante barges in telling them that they are all doomed and that a "pestilence" is coming. After noticing Diesel scratching, Dylan deduces that he might have fleas and asks Dolly if she cleaned up with everyone like he did. She denies this and admits that they found a bouncy disused mattress in the dumpster and started playing with it. Believing that this is what is causing the fleas to spread, Dylan dresses up in his space suit and begins to quarantine everyone into the basement until their is only himself, Dolly, Dawkins and Dante left. Dolly remembers that Dorothy is still by the mattress and goes to pick her up. They soon find out that they are out of flea powder (Dylan was supposed to be in charge of restocking) and that they will not be able to order anymore until tomorrow.
The group is shocked by the arrival of Triple-D whom Dylan hugs upon seeing that they are okay. However, they soon begin to itch and are quarantined as well, which confuses Dawkins as they were nowhere near the mattress and thus it could not be the cause. The dalmatians further realize that they cannot leave the premises as they could risk spreading the fleas to the other dogs in Camden Town. Dante suddenly comes down with itching and he too is quarantined off. As Dolly wonders what they could be missing, the power suddenly goes out allowing the other dalmatians to escape the basement and head upstairs.
Dylan, Dolly, Dawkins and Dorothy escape out the bathroom window and head to the roof where Dorothy suddenly becomes infected. The other three escape to the tree house, all the while Clarissa mocks their unfortunate situation. Dolly and Dawkins suddenly begin to itch and Dylan has an epiphany. His space rock, which was given to him by Clarissa and which he had worn around his neck, had been carrying the fleas this entire time. He was not infected because he had bathed. Dylan then gets dirty to attract all the fleas to him and bounces over to Clarissa's house, severely infecting her, much to her horror.
- Josh Brener as Dylan
- Michaela Dietz as Dolly
- Rhys Isaac-Jones as Dawkins
- Kyle Soller as Dante
- Bert Davis as Diesel
- Lauren Lindsey Donzis as Destiny and Déjà Vu
- Abigail Zoe Lewis as Dallas
- Margot Powell as Dorothy
- Nefeli Karakosta as Dizzy
- Florrie Wilkinson as Dee Dee
- Nikhil Parmar as Deepak
- Rocco Wright as the Dimitri Trio
- Harriet Carmichael as Clarissa the Corgi
- Rufus Jones as Hugo
- This episode is a parody of the zombie film genre.
- This episode is similar to the The Loud House episode "One Flu Over the Loud House".
- Dylan performs a parody of "Thriller" in this episode.
- Before Dante is lowered into the basement, Dylan tells him "I love you", to which Dante responds "I know", similar to an exchange between Leia Organa and Han Solo in Star Wars Episode V: The Empire Strikes Back.